Tangential belts of the above-described kind are used,for instance, in ring spinning machines, ring twisting machines, open-end rotor spinning machines or open-end friction spinning machines, or the like. In these machines, the work units, such as spindles, rotors, or release rollers or the like, are arranged in one or two rows and driven by tangential belts, oncoming against the whorl of the work units. It is common practice to have the drive of the tangential belt in the area of one frontal end of the machine and the guide means in the area of the other frontal end. As a result of the belt contact at the whorls and the necessary contact rollers, a considerable energy consumption and belt wear are characteristic for the plurality of the work units, due to fulling. This energy consumption and belt wear increases with the increasing number of work units, but all together also per unit, since the tangential belt has to be thicker and/or wider for transmitting the required output when the number of work units has been increased. Since the number of working units, for instance in a ring machine, can be of 1000 and more, in practice, tangential belts with a width of 35 to 38 mm and a thickness of 3 to 3.7 mm are used.
In order to reduce the load on a tangential belt running through the entire machine, it is also known (German open application No. 33 01 811) to provide at both ends of the machine at least one electromotor and to use the already provided guide disks as drive means for the tangential belt. Driven guiding disks are therefore preferably provided in each of the four guiding spots of the tangential belt . In addition, it has also become known (PCT-WO No. 84/02 932) to introduce a further drive for the tangential belt in at least one additional spot, between the ends of the machine, by means of a driven friction disk. The success of this measure, with regard to the load on the tangential belt is, however, limited.
A tangential-belt drive is also known (German published specification No. 11 41 571) wherein the work units arranged next to each other in rows, are subdivided into sections which have at least approximately the same number of work units, each driven by means of an endless tangential belt. To each of these tangential belts of a section, an electromotor and guiding means are assigned. In this type of construction, the tangential belt drives intermediate rollers, which, at their turn, drive the work units over smaller endless belts. This construction type of a tangential-belt drive has not found any practical use.
It is the object of this invention to create a tangential-belt drive of the afore-described kind, wherein losses of work capacity and/or belt loads can be reduced.